For x-ray systems with multiple focal spot sizes and target materials that are automatically selected by the system, how is it possible for the system to indicate the selected focal spot or target material before the exposure is taken?
When focal spot size and/or target material are automatically selected by the system, the system must show the pre-exposure values that are set either by the technologist, by the unit, or by default. Once the exposure has been completed, the system must then display the focal spot size and/or target material actually used during the exposure. The unit must indicate these pre-exposure values, either on the unit or at the operator position, prior to the exposure and then indicate the actual values used during the exposure, as required in 900.12(b)(7)(iii). The indication must be clear and legible and can be achieved in any manner that provides the required information in an unambiguous fashion.